Microfluidic systems offer potential advantage in applications such as chemical synthesis, distillation, and analysis. Such systems typically include one or more flow channels interconnected to chambers where minute volumes of fluids are introduced, extracted, separated, reacted, or dissociated into constituent components. In order for a microfluidic system to operate properly, the flow of analytes contained in the solutions that flow through the flow channels must be carefully controlled.
Often, a microfluidic system distributes buffered electrolyte containing one or more analytes through its flow channels by means of electroosmotic flow. Electroosmotic flow is achieved by means of an applied high electric field. In the presence of the electric field, ions are pulled through the flow channel. In some applications, such as capillary electrophoresis, the analytes separate within the flow channel due to differences in their electrophoretic mobility. As a result, separate chemicals or chemical compounds can be identified by the rate at which they flow through the flow channel. In some applications, the separated chemical compounds can be routed to different areas of the microfluidic system where they can take part in desired chemical reactions, be further separated, or be extracted from the system.
In many cases, the flow of analyte through the microfluidic system is not well controlled due to physical and electrical effects associated with the channel walls. These effects can create uncertainty in the detection of the analyte or errors in the introduction of an analyte into a chemical reaction.